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by gods
on Aug 24, 1999 at 22:41 UTC ( #183=perlfunc: print w/replies, xml ) Need Help??


See the current Perl documentation for each.

Here is our local, out-dated (pre-5.6) version:

each - retrieve the next key/value pair from a hash

each HASH

When called in list context, returns a 2-element list consisting of the key and value for the next element of a hash, so that you can iterate over it. When called in scalar context, returns the key for only the ``next'' element in the hash. (Note: Keys may be "0" or "", which are logically false; you may wish to avoid constructs like while ($k = each %foo) {} for this reason.)

Entries are returned in an apparently random order. When the hash is entirely read, a null array is returned in list context (which when assigned produces a FALSE ( 0) value), and undef in scalar context. The next call to each() after that will start iterating again. There is a single iterator for each hash, shared by all each(), keys(), and values() function calls in the program; it can be reset by reading all the elements from the hash, or by evaluating keys HASH or values HASH. If you add or delete elements of a hash while you're iterating over it, you may get entries skipped or duplicated, so don't.

The following prints out your environment like the printenv(1) program, only in a different order:

    while (($key,$value) = each %ENV) {
        print "$key=$value\n";

See also keys() and values().

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[Corion]: LanX: Maybe have an infinite-loop cmd file? Much easier than trying to manage that from within Perl IMO
[Corion]: Alternatively, relaunch the application from cron (or a Windows cron) every minute
[LanX]: will try infinite loop ...
[Corion]: :START ... goto START
[LanX]: oh .bat you mean?
[LanX]: obscure cult ...
[Corion]: LanX: cmd.exe is just another way to launch Perl
[LanX]: I know its a cult... and I repent it every time
[LanX]: But cygwin comes with path problems and powershell requires too much learning for me
[LanX]: eshell in emacs is often my resort in development

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